A sensitive and rapid liquid chromatography-tandem mass spectrometry(LC–MS/MS) method has been developed for the simultaneous determination of lisinopril(LIS) and hydrochlorothiazide(HCTZ) in human plasma using their...A sensitive and rapid liquid chromatography-tandem mass spectrometry(LC–MS/MS) method has been developed for the simultaneous determination of lisinopril(LIS) and hydrochlorothiazide(HCTZ) in human plasma using their labeled internal standards(ISs). Sample pre-treatment involved solid phase extraction on Waters Oasis HLB cartridges using 100 μL of plasma, followed by liquid chromatography on Hypersil Gold C_(18)(50 mm×3.0 mm, 5 μm) column. The analytes were eluted within 2.0 min using acetonitrile-5.0 m M ammonium formate, p H 4.5(85:15, v/v) as the mobile phase. The analytes and ISs were analyzed in the negative ionization mode and quantified using multiple reaction monitoring. The method showed excellent linearity over the concentration range of 0.50–250.0 ng/m L for both the analytes. The intra-batch and inter-batch precision(% CV) was ≤5.26% and their extraction recoveries were in the range of 96.6%–103.1%. Matrix effect evaluated in terms of IS-normalized matrix factors ranged from 0.97 to 1.03 for both the analytes. The validated method was successfully applied to determine the plasma concentration of the drugs using 10 mg lisinopril and 12.5 mg hydrochlorothiazide fixed dose formulation in 18 healthy Indian volunteers.展开更多
A sensitive and selective method has been proposed for the simultaneous determination of amlodipine(AML),valsartan(VAL) and hydrochlorothiazide(HCTZ) in human plasma by liquid chromatography–tandem mass spectrometry...A sensitive and selective method has been proposed for the simultaneous determination of amlodipine(AML),valsartan(VAL) and hydrochlorothiazide(HCTZ) in human plasma by liquid chromatography–tandem mass spectrometry(LC–MS/MS). The analytes and their deuterated analogs were quantitatively extracted from100 μL human plasma by solid phase extraction on Oasis HLB cartridges. The chromatographic separation of the analytes was achieved on a Chromolith RP18 e(100 mm × 4.6 mm) analytical column within 2.5 min. The resolution factor between AML and VAL, AML and HCTZ, and VAL and HCTZ was 2.9, 1.5 and 1.4, respectively,under isocratic conditions. The method was validated over a dynamic concentration range of 0.02–20.0 ng/m L for AML, 5.00–10,000 ng/m L for VAL and 0.20–200 ng/m L for HCTZ. Ion-suppression/enhancement effects were investigated by post-column infusion technique. The mean IS-normalized matrix factors for AML, VAL and HCTZ were 0.992, 0.994 and 0.998, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was ≤ 5.56% and the recovery was in the range of 93.4%–99.6% for all the analytes. The method was successfully applied to a bioequivalence study of 5 mg AML + 160 mg VAL + 12.5 mg HCTZ tablet formulation(test and reference) in 18 healthy Indian males under fasting. The mean log-transformed ratios of C max, AUC0–120 h and AUC0-inf and their 90% CIs were within 90.2%–102.1%. The assay reproducibility was demonstrated by reanalysis of 90 incurred samples.展开更多
The aim of the present investigation was to demonstrate an approach involving use of liquid chromatography(LC) and liquid chromatography-mass spectrometry(LC–MS) to separate, identify and characterize very small quan...The aim of the present investigation was to demonstrate an approach involving use of liquid chromatography(LC) and liquid chromatography-mass spectrometry(LC–MS) to separate, identify and characterize very small quantities of degradation products(DPs) of acebutolol without their isolation from the reaction mixtures. The drug was subjected to oxidative, hydrolytic, thermal and photolytic stress conditions as per International Conference on Harmonization(ICH) guideline Q1 A(R2). Among all the stress conditions the drug was found to be labile in hydrolytic(acidic & basic) and photolytic stress conditions, while it was stable in water-induced hydrolysis, oxidative and thermal stress conditions. A total of four degradation products were formed. A C18 column was employed for the separation of all the DPs on a gradient mode by using high-performance liquid chromatography(HPLC). All the DPs were characterized with the help of their fragmentation pattern and the masses obtained upon LC–MS/MS and MSnanalysis. All the hitherto unknown degradation products were identified as 1-(2-(2-hydroxy-3-(isopropylamino)propoxy)-5-(amino)phenyl)ethanone(DP-I), N-(4-(2-hydroxy-3-(isopropylamino)propoxy)-3-acetylphenyl)acrylamide(DP-II), 1-(2-(2-hydroxy-3-(isopropylamino)propoxy)-5-(hydroxymethylamino)phenyl)ethanone(DP-III) and 1-(6-(2-hydroxy-3-(isopropylamino)propoxy)-2,3-dihydro-2-propylbenzo[d]oxazol-5-yl)ethanone(DP-IV). Finally the in-silico carcinogenicity and hepatotoxicity predictions of the drug and all the DPs were performed by using toxicity prediction softwares viz., TOPKAT, LAZAR and Discovery Studio ADMET. The results of in-silico toxicity studies revealed that acebutolol(0.967) and DP-I(0.986) were found to be carcinogenic, while acebutolol(0.490) and DP-IV(0.437) were found to be hepatotoxic.展开更多
Electrospray ionization(ESI) and atmospheric pressure chemical ionization(APCI) techniques for liquid chromatography–tandem mass spectrometry(LC–MS/MS) determination of levonorgestrel were evaluated.In consideration...Electrospray ionization(ESI) and atmospheric pressure chemical ionization(APCI) techniques for liquid chromatography–tandem mass spectrometry(LC–MS/MS) determination of levonorgestrel were evaluated.In consideration of difference in ionization mechanism,the two ionization sources were compared in terms of LC conditions,MS parameters and performance of method.The sensitivity for detection of levonorgestrel with ESI was 0.25 ng/m L which was lower than 1 ng/m L with APCI.Matrix effects were evaluated for levonorgestrel and canrenone(internal standard,IS) in human plasma,and the results showed that APCI source appeared to be slightly less liable to matrix effect than ESI source.With an overall consideration,ESI was chosen as a better ionization technique for rapid and sensitive quantification of levonorgestrel.The optimized LC–ESI–MS/MS method was validated for a linear range of 0.25–50 ng/m L with a correlation coefficient ≥0.99.The intra-and inter-batch precision and accuracy were within 11.72% and 6.58%,respectively.The application of this method was demonstrated by a bioequivalence study following a single oral administration of 1.5 mg levonorgestrel tablets in 21 Chinese healthy female volunteers.展开更多
A sensitive and selective method was developed for the separation and characterization of related substances(RSs) in EVT-401 by hyphenated LC–MS techniques. Complete separation of the RSs was achieved with an Inertsi...A sensitive and selective method was developed for the separation and characterization of related substances(RSs) in EVT-401 by hyphenated LC–MS techniques. Complete separation of the RSs was achieved with an Inertsil ODS-SP column(250 mm×4.6 mm, 5 μm) by linear gradient elution using a mobile phase consisting of 0.2% formic acid solution, methanol and acetonitrile. EVT-401 was found to be susceptible to acid, alkaline and oxidative stresses, while relatively stable under photolytic and thermal dry stress conditions. Fourteen RSs including six process-related substances and eight degradation products were detected and identified in EVT-401 with positive ESI high-resolution TOF-MS analysis of their parent ions and the corresponding product mass spectra elucidation, and some of them were further verified by chemical synthesis and NMR spectroscopy. The specific LC–MS method developed for separation, identification and characterization of RSs is valuable for EVT-401 manufacturing process optimization and quality control.展开更多
A selective, sensitive and rugged liquid chromatography–tandem mass spectrometry(LC–MS/MS) assay has been developed for the simultaneous determination of doxepin(Dox) and its pharmacologically active metabolite, nor...A selective, sensitive and rugged liquid chromatography–tandem mass spectrometry(LC–MS/MS) assay has been developed for the simultaneous determination of doxepin(Dox) and its pharmacologically active metabolite, nordoxepin(NDox) in human plasma. The analytes and their internal standards(IS)were extracted from 500 m L of human plasma by liquid-liquid extraction using methyl tert-butyl ether.Chromatographic separation was achieved on Hypurity C8 column(100 mm ? 4.6 mm, 5 mm) using a mixture of acetonitrile-methanol(95:5, v/v) and 2.0 mM ammonium formate in 93:7(v/v) ratio. Detection was accomplished by tandem mass spectrometry in the positive ionization and multiple reaction monitoring acquisition mode. The protonated precursor to product ion transitions studied for Dox, NDox,and their corresponding ISs, propranolol and desipramine, were m/z 280.1-107.0, 266.0-107.0,260.1-116.1 and 267.1-72.1, respectively. A linear dynamic range of 15.0–3900 pg/mL for Dox and 5.00–1300 pg/mL for NDox was established with mean correlation coefficient(r2) of 0.9991 and 0.9993, respectively. The extraction recovery ranged from 86.6%–90.4% and 88.0%–99.1% for Dox and NDox, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was r 8.3% for both the analytes. Stability evaluated under different storage conditions showed no evidence of degradation and the % change in stability samples compared to nominal concentration ranged from 4.7% to12.3%. The method was successfully applied to a bioequivalence study of 6 mg doxepin hydrochloride orally disintegrating tablet in 41 healthy Indian subjects under fasting and fed conditions.展开更多
A highly sensitive, rapid and rugged liquid chromatography-tandem mass spectrometry(LC-ESI-MS/MS)method was developed for reliable estimation of amantadine(AMD), an antiviral drug in human plasma.The analyte and inter...A highly sensitive, rapid and rugged liquid chromatography-tandem mass spectrometry(LC-ESI-MS/MS)method was developed for reliable estimation of amantadine(AMD), an antiviral drug in human plasma.The analyte and internal standard(IS), amantadine-d6(AMD-d6), were extracted from 200 m L plasma by solid phase extraction on Phenomenex Strata-X-C 33 m cartridges. Chromatography was performed on Synergi? Hydro-RP C18(150 mm ? 4.6 mm, 4 mm) analytical column using a mixture of acetonitrile and10 m M ammonium formate, p H 3.0(80:20, v/v) as the mobile phase. Detection and quantitation was done by multiple reaction monitoring in the positive ionization mode for AMD(m/z 152.1-135.1) and IS(m/z 158.0-141.1) on a triple quadrupole mass spectrometer. The assay was linear in the concentration range of 0.50–500 ng/m L with correlation coefficient(r2) Z 0.9969. The limit of detection of the method was 0.18 ng/m L. The intra-batch and inter-batch precisions were r 5.42% and the accuracy varied from98.47% to 105.72%. The extraction recovery of amantadine was precise and quantitative in the range of97.89%–100.28%. IS-normalized matrix factors for amantadine varied from 0.981 to 1.012. The stability of AMD in whole blood and plasma was evaluated under different conditions. The developed method was successfully applied for a bioequivalence study with 100 mg of AMD in 32 healthy volunteers. The reproducibility of the assay was determined by reanalysis of 134 subject samples.展开更多
A sensitive method based on high-performance liquid chromatography–tandem mass spectrometry(LC–MS/MS) has been developed for the simultaneous determination of folic acid(FA) and its active metabolite, 5-methyltetrah...A sensitive method based on high-performance liquid chromatography–tandem mass spectrometry(LC–MS/MS) has been developed for the simultaneous determination of folic acid(FA) and its active metabolite, 5-methyltetrahydrofolic acid(5-M-THF), in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/m L of 2-mercaptoethanol and 0.025%(v/v) ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 m M ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC–MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring(MRM) mode. The assay was linear over the concentration ranges of 0.249–19.9 ng/m L for FA,and 5.05–50.5 ng/m L for 5-M-THF. The developed LC–MS/MS method offers increased sensitivity for quanti fi cation of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.展开更多
A metabolic profile of plasma samples from patients undergoing heart surgery with the use of cardiopulmonary bypass(CPB) and concurrent administration of tranexamic acid was determined.Direct immersion solid phase mic...A metabolic profile of plasma samples from patients undergoing heart surgery with the use of cardiopulmonary bypass(CPB) and concurrent administration of tranexamic acid was determined.Direct immersion solid phase microextraction(DI-SPME), a new sampling and sample preparation tool for metabolomics, was used in this study for the first time to investigate clinical samples. The results showed alteration of diverse compounds involved in different biochemical pathways. The most significant contribution in changes induced by surgery and applied pharmacotherapy was noticed in metabolic profile of lysophospholipids, triacylglycerols, mediators of platelet aggregation, and linoleic acid metabolites.Two cases of individual response to treatment were also reported.展开更多
Zidvovudine(AZT) is a nucleoside analogue reverse transcriptase inhibitor(NRTI), a class of anti-retroviral drug. A stability-indicating assay method for AZT was developed in line with ICH guideline. Successful separa...Zidvovudine(AZT) is a nucleoside analogue reverse transcriptase inhibitor(NRTI), a class of anti-retroviral drug. A stability-indicating assay method for AZT was developed in line with ICH guideline. Successful separation of AZT and its degradation products was achieved by gradient elution mode on reverse phase C_(18) column using 10 mM ammonium acetate: acetonitrile as the mobile phase at 0.8 mL/min flow rate, 25 μL injection volume, 30 °C column temperature and 285 nm detection wavelength. Two major acid degradation products were identified and characterized by liquid chromatography–electrospray ionization mass spectrometry(LC–ESI/MS/MS) and accurate mass measurements. The probable mechanisms for the formation of degradation products were identified based on a comparison of the fragmentation pattern of the [M + H]^+ions of AZT and its degradation products. One of the degradation products, DP-1, was isolated by semi-preparative high performance liquid chromatography(HPLC) using Waters XBridge Prep C_(18)(250 mm×10 mm, 5 μm).Degradation products showed higher toxicity compared to the drug in some models assessed by TOPKAT software. The method validation was performed with respect to robustness, specificity, linearity, precision and accuracy as per ICH guideline Q2(R1).展开更多
A simple and rapid liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed and validated for simultaneous determination of acetaminophen and oxycodone in human plasma. Acetaminophen-d4 and oxyc...A simple and rapid liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed and validated for simultaneous determination of acetaminophen and oxycodone in human plasma. Acetaminophen-d4 and oxycodone-d3 were used as internal standards. The challenge encountered in the method development that the high plasma concentration level of acetaminophen made the MS response saturated while the desired lower limit of quantification(LLOQ) for oxycodone was hard to reach was well solved. The analytes were extracted by protein precipitation using acetonitrile. The matrix effect of the analytes was avoided by chromatographic separation using a hydrophilic C18 column coupled with gradient elution. Multiple reaction monitoring in positive ion mode was performed on tandem mass spectrometer employing electrospray ion source. The calibration curves were linear over the concentration ranges of 40.0–8000 ng/m L and 0.200–40.0 ng/m L for acetaminophen and oxycodone,respectively. This method, which could contribute to high throughput analysis and better clinical drug monitoring, was successfully applied to a pharmacokinetic study in healthy Chinese volunteers.展开更多
Deoxyglycychloxazol(TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activity and reduced pseudoaldosteronism compared to glycyrrhetinic acid.In this study,a sensitive and rapid liquid ...Deoxyglycychloxazol(TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activity and reduced pseudoaldosteronism compared to glycyrrhetinic acid.In this study,a sensitive and rapid liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was established for the quantitation of TY501 in rat plasma.Plasma samples were treated by precipitating protein with methanol and supernatants were separated by a Symmetry C_8 column with the mobile phase consisting of methanol and 10 m M ammonium formate(containing 0.1% of formic acid)(90:10,v/v).The selected reaction monitoring(SRM) transitions were performed at m/z 647.4-191.2 for TY501 and m/z 473.3-143.3 for astragaloside aglycone(IS) in the positive ion mode with atmospheric pressure chemical ionization(APCI) source.Calibration curve was linear over the concentration range of 5–5000 ng/m L.The lower limit of quantification was 5 ng/m L.The mean recovery was over 88%.The intra- and inter-day precisions were lower than 6.0% and 12.8%,respectively,and the accuracy was within 7 1.3%.TY501 was stable under usual storage conditions and handling procedure.The validated method has been successfully applied to a pharmacokinetic study after oral administration of TY501 to rats at a dosage of 10 mg/kg.展开更多
Liquid chromatography tandem mass chromatography(LC–MS/MS)is an important hyphenated technique for quantitative analysis of drugs in biological fuids.Because of high sensitivity and selectivity,LC–MS/MS has been use...Liquid chromatography tandem mass chromatography(LC–MS/MS)is an important hyphenated technique for quantitative analysis of drugs in biological fuids.Because of high sensitivity and selectivity,LC–MS/MS has been used for pharmacokinetic studies,metabolites identifcation in the plasma and urine.This manuscript gives comprehensive analytical review,focusing on chromatographic separation approaches(column packing materials,column length and mobile phase)as well as different acquisition modes(SIM,MRM)for quantitative analysis of glucocorticoids and stimulants.This review is not meant to be exhaustive but rather to provide a general overview for detection and confrmation of target drugs using LC–MS/MS and thus useful in the doping analysis,toxicological studies as well as in pharmaceutical analysis.展开更多
Management of cardiovascular risk factors in diabetes demands special attention due to their co-existence.Pioglitazone(PIO) and telmisartan(TLM) combination can be beneficial in effective control of cardiovascular com...Management of cardiovascular risk factors in diabetes demands special attention due to their co-existence.Pioglitazone(PIO) and telmisartan(TLM) combination can be beneficial in effective control of cardiovascular complication in diabetes. In this research, we developed and validated a high throughput LC–MS/MS method for simultaneous quantitation of PIO and TLM in rat plasma. This developed method is more sensitive and can quantitate the analytes in relatively shorter period of time compared to the previously reported methods for their individual quantification. Moreover, till date, there is no bioanalytical method available to simultaneously quantitate PIO and TLM in a single run. The method was validated according to the USFDA guidelines for bioanalytical method validation. A linear response of the analytes was observed over the range of 0.005–10 μg/m L with satisfactory precision and accuracy. Accuracy at four quality control levels was within 94.27%–106.10%.The intra-and inter-day precision ranged from 2.32% to 10.14% and 5.02% to 8.12%, respectively. The method was reproducible and sensitive enough to quantitate PIO and TLM in rat plasma samples of a preclinical pharmacokinetic study. Due to the potential of PIO-TLM combination to be therapeutically explored, this method is expected to have significant usefulness in future.展开更多
A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry(UPLC–MS/MS) method was developed and validated for the estimation of 17-desacetyl norgestimate in human plasma using solid-phase...A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry(UPLC–MS/MS) method was developed and validated for the estimation of 17-desacetyl norgestimate in human plasma using solid-phase extraction technique. 17-desacetyl norgestimate D6 was used as the internal standard. Simple gradient chromatographic conditions and mass spectrometric detection enabled accurate and precise measurement of 17-desacetyl norgestimate at sub-picogram levels. The proposed method was validated for a linear range of 20–5000 pg/m L with a correlation coefficient Z 0.9988. The intra-run and inter-run precision and accuracy were within 10%. The overall recoveries for 17-desacetyl norgestimate and 17-desacetyl norgestimate D6 were 96.30% and 93.90%, respectively. The total run time was 4.5 min. The developed method was applied for the determination of the pharmacokinetic parameters of 17-desacetyl norgestimate following a single oral administration of a norgestimate and ethinyl estradiol0.250 mg/0.035 mg tablets in 35 healthy female volunteers.展开更多
基金University Grants Commission (UGC), New Delhi, India for BSR fellowship F 4-1/2009 (BSR)/7-74/2007the Department of Chemistry, Gujarat University
文摘A sensitive and rapid liquid chromatography-tandem mass spectrometry(LC–MS/MS) method has been developed for the simultaneous determination of lisinopril(LIS) and hydrochlorothiazide(HCTZ) in human plasma using their labeled internal standards(ISs). Sample pre-treatment involved solid phase extraction on Waters Oasis HLB cartridges using 100 μL of plasma, followed by liquid chromatography on Hypersil Gold C_(18)(50 mm×3.0 mm, 5 μm) column. The analytes were eluted within 2.0 min using acetonitrile-5.0 m M ammonium formate, p H 4.5(85:15, v/v) as the mobile phase. The analytes and ISs were analyzed in the negative ionization mode and quantified using multiple reaction monitoring. The method showed excellent linearity over the concentration range of 0.50–250.0 ng/m L for both the analytes. The intra-batch and inter-batch precision(% CV) was ≤5.26% and their extraction recoveries were in the range of 96.6%–103.1%. Matrix effect evaluated in terms of IS-normalized matrix factors ranged from 0.97 to 1.03 for both the analytes. The validated method was successfully applied to determine the plasma concentration of the drugs using 10 mg lisinopril and 12.5 mg hydrochlorothiazide fixed dose formulation in 18 healthy Indian volunteers.
文摘A sensitive and selective method has been proposed for the simultaneous determination of amlodipine(AML),valsartan(VAL) and hydrochlorothiazide(HCTZ) in human plasma by liquid chromatography–tandem mass spectrometry(LC–MS/MS). The analytes and their deuterated analogs were quantitatively extracted from100 μL human plasma by solid phase extraction on Oasis HLB cartridges. The chromatographic separation of the analytes was achieved on a Chromolith RP18 e(100 mm × 4.6 mm) analytical column within 2.5 min. The resolution factor between AML and VAL, AML and HCTZ, and VAL and HCTZ was 2.9, 1.5 and 1.4, respectively,under isocratic conditions. The method was validated over a dynamic concentration range of 0.02–20.0 ng/m L for AML, 5.00–10,000 ng/m L for VAL and 0.20–200 ng/m L for HCTZ. Ion-suppression/enhancement effects were investigated by post-column infusion technique. The mean IS-normalized matrix factors for AML, VAL and HCTZ were 0.992, 0.994 and 0.998, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was ≤ 5.56% and the recovery was in the range of 93.4%–99.6% for all the analytes. The method was successfully applied to a bioequivalence study of 5 mg AML + 160 mg VAL + 12.5 mg HCTZ tablet formulation(test and reference) in 18 healthy Indian males under fasting. The mean log-transformed ratios of C max, AUC0–120 h and AUC0-inf and their 90% CIs were within 90.2%–102.1%. The assay reproducibility was demonstrated by reanalysis of 90 incurred samples.
文摘The aim of the present investigation was to demonstrate an approach involving use of liquid chromatography(LC) and liquid chromatography-mass spectrometry(LC–MS) to separate, identify and characterize very small quantities of degradation products(DPs) of acebutolol without their isolation from the reaction mixtures. The drug was subjected to oxidative, hydrolytic, thermal and photolytic stress conditions as per International Conference on Harmonization(ICH) guideline Q1 A(R2). Among all the stress conditions the drug was found to be labile in hydrolytic(acidic & basic) and photolytic stress conditions, while it was stable in water-induced hydrolysis, oxidative and thermal stress conditions. A total of four degradation products were formed. A C18 column was employed for the separation of all the DPs on a gradient mode by using high-performance liquid chromatography(HPLC). All the DPs were characterized with the help of their fragmentation pattern and the masses obtained upon LC–MS/MS and MSnanalysis. All the hitherto unknown degradation products were identified as 1-(2-(2-hydroxy-3-(isopropylamino)propoxy)-5-(amino)phenyl)ethanone(DP-I), N-(4-(2-hydroxy-3-(isopropylamino)propoxy)-3-acetylphenyl)acrylamide(DP-II), 1-(2-(2-hydroxy-3-(isopropylamino)propoxy)-5-(hydroxymethylamino)phenyl)ethanone(DP-III) and 1-(6-(2-hydroxy-3-(isopropylamino)propoxy)-2,3-dihydro-2-propylbenzo[d]oxazol-5-yl)ethanone(DP-IV). Finally the in-silico carcinogenicity and hepatotoxicity predictions of the drug and all the DPs were performed by using toxicity prediction softwares viz., TOPKAT, LAZAR and Discovery Studio ADMET. The results of in-silico toxicity studies revealed that acebutolol(0.967) and DP-I(0.986) were found to be carcinogenic, while acebutolol(0.490) and DP-IV(0.437) were found to be hepatotoxic.
文摘Electrospray ionization(ESI) and atmospheric pressure chemical ionization(APCI) techniques for liquid chromatography–tandem mass spectrometry(LC–MS/MS) determination of levonorgestrel were evaluated.In consideration of difference in ionization mechanism,the two ionization sources were compared in terms of LC conditions,MS parameters and performance of method.The sensitivity for detection of levonorgestrel with ESI was 0.25 ng/m L which was lower than 1 ng/m L with APCI.Matrix effects were evaluated for levonorgestrel and canrenone(internal standard,IS) in human plasma,and the results showed that APCI source appeared to be slightly less liable to matrix effect than ESI source.With an overall consideration,ESI was chosen as a better ionization technique for rapid and sensitive quantification of levonorgestrel.The optimized LC–ESI–MS/MS method was validated for a linear range of 0.25–50 ng/m L with a correlation coefficient ≥0.99.The intra-and inter-batch precision and accuracy were within 11.72% and 6.58%,respectively.The application of this method was demonstrated by a bioequivalence study following a single oral administration of 1.5 mg levonorgestrel tablets in 21 Chinese healthy female volunteers.
文摘A sensitive and selective method was developed for the separation and characterization of related substances(RSs) in EVT-401 by hyphenated LC–MS techniques. Complete separation of the RSs was achieved with an Inertsil ODS-SP column(250 mm×4.6 mm, 5 μm) by linear gradient elution using a mobile phase consisting of 0.2% formic acid solution, methanol and acetonitrile. EVT-401 was found to be susceptible to acid, alkaline and oxidative stresses, while relatively stable under photolytic and thermal dry stress conditions. Fourteen RSs including six process-related substances and eight degradation products were detected and identified in EVT-401 with positive ESI high-resolution TOF-MS analysis of their parent ions and the corresponding product mass spectra elucidation, and some of them were further verified by chemical synthesis and NMR spectroscopy. The specific LC–MS method developed for separation, identification and characterization of RSs is valuable for EVT-401 manufacturing process optimization and quality control.
文摘A selective, sensitive and rugged liquid chromatography–tandem mass spectrometry(LC–MS/MS) assay has been developed for the simultaneous determination of doxepin(Dox) and its pharmacologically active metabolite, nordoxepin(NDox) in human plasma. The analytes and their internal standards(IS)were extracted from 500 m L of human plasma by liquid-liquid extraction using methyl tert-butyl ether.Chromatographic separation was achieved on Hypurity C8 column(100 mm ? 4.6 mm, 5 mm) using a mixture of acetonitrile-methanol(95:5, v/v) and 2.0 mM ammonium formate in 93:7(v/v) ratio. Detection was accomplished by tandem mass spectrometry in the positive ionization and multiple reaction monitoring acquisition mode. The protonated precursor to product ion transitions studied for Dox, NDox,and their corresponding ISs, propranolol and desipramine, were m/z 280.1-107.0, 266.0-107.0,260.1-116.1 and 267.1-72.1, respectively. A linear dynamic range of 15.0–3900 pg/mL for Dox and 5.00–1300 pg/mL for NDox was established with mean correlation coefficient(r2) of 0.9991 and 0.9993, respectively. The extraction recovery ranged from 86.6%–90.4% and 88.0%–99.1% for Dox and NDox, respectively. The intra-batch and inter-batch precision(% CV) across quality control levels was r 8.3% for both the analytes. Stability evaluated under different storage conditions showed no evidence of degradation and the % change in stability samples compared to nominal concentration ranged from 4.7% to12.3%. The method was successfully applied to a bioequivalence study of 6 mg doxepin hydrochloride orally disintegrating tablet in 41 healthy Indian subjects under fasting and fed conditions.
文摘A highly sensitive, rapid and rugged liquid chromatography-tandem mass spectrometry(LC-ESI-MS/MS)method was developed for reliable estimation of amantadine(AMD), an antiviral drug in human plasma.The analyte and internal standard(IS), amantadine-d6(AMD-d6), were extracted from 200 m L plasma by solid phase extraction on Phenomenex Strata-X-C 33 m cartridges. Chromatography was performed on Synergi? Hydro-RP C18(150 mm ? 4.6 mm, 4 mm) analytical column using a mixture of acetonitrile and10 m M ammonium formate, p H 3.0(80:20, v/v) as the mobile phase. Detection and quantitation was done by multiple reaction monitoring in the positive ionization mode for AMD(m/z 152.1-135.1) and IS(m/z 158.0-141.1) on a triple quadrupole mass spectrometer. The assay was linear in the concentration range of 0.50–500 ng/m L with correlation coefficient(r2) Z 0.9969. The limit of detection of the method was 0.18 ng/m L. The intra-batch and inter-batch precisions were r 5.42% and the accuracy varied from98.47% to 105.72%. The extraction recovery of amantadine was precise and quantitative in the range of97.89%–100.28%. IS-normalized matrix factors for amantadine varied from 0.981 to 1.012. The stability of AMD in whole blood and plasma was evaluated under different conditions. The developed method was successfully applied for a bioequivalence study with 100 mg of AMD in 32 healthy volunteers. The reproducibility of the assay was determined by reanalysis of 134 subject samples.
文摘A sensitive method based on high-performance liquid chromatography–tandem mass spectrometry(LC–MS/MS) has been developed for the simultaneous determination of folic acid(FA) and its active metabolite, 5-methyltetrahydrofolic acid(5-M-THF), in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/m L of 2-mercaptoethanol and 0.025%(v/v) ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 m M ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC–MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring(MRM) mode. The assay was linear over the concentration ranges of 0.249–19.9 ng/m L for FA,and 5.05–50.5 ng/m L for 5-M-THF. The developed LC–MS/MS method offers increased sensitivity for quanti fi cation of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.
基金the Natural Sciences and Engineering Research Council of Canada Industrial Research Chairs (NSERC IRC) and the Canada Research Chairs (CRC) for financial support of the project
文摘A metabolic profile of plasma samples from patients undergoing heart surgery with the use of cardiopulmonary bypass(CPB) and concurrent administration of tranexamic acid was determined.Direct immersion solid phase microextraction(DI-SPME), a new sampling and sample preparation tool for metabolomics, was used in this study for the first time to investigate clinical samples. The results showed alteration of diverse compounds involved in different biochemical pathways. The most significant contribution in changes induced by surgery and applied pharmacotherapy was noticed in metabolic profile of lysophospholipids, triacylglycerols, mediators of platelet aggregation, and linoleic acid metabolites.Two cases of individual response to treatment were also reported.
文摘Zidvovudine(AZT) is a nucleoside analogue reverse transcriptase inhibitor(NRTI), a class of anti-retroviral drug. A stability-indicating assay method for AZT was developed in line with ICH guideline. Successful separation of AZT and its degradation products was achieved by gradient elution mode on reverse phase C_(18) column using 10 mM ammonium acetate: acetonitrile as the mobile phase at 0.8 mL/min flow rate, 25 μL injection volume, 30 °C column temperature and 285 nm detection wavelength. Two major acid degradation products were identified and characterized by liquid chromatography–electrospray ionization mass spectrometry(LC–ESI/MS/MS) and accurate mass measurements. The probable mechanisms for the formation of degradation products were identified based on a comparison of the fragmentation pattern of the [M + H]^+ions of AZT and its degradation products. One of the degradation products, DP-1, was isolated by semi-preparative high performance liquid chromatography(HPLC) using Waters XBridge Prep C_(18)(250 mm×10 mm, 5 μm).Degradation products showed higher toxicity compared to the drug in some models assessed by TOPKAT software. The method validation was performed with respect to robustness, specificity, linearity, precision and accuracy as per ICH guideline Q2(R1).
文摘A simple and rapid liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed and validated for simultaneous determination of acetaminophen and oxycodone in human plasma. Acetaminophen-d4 and oxycodone-d3 were used as internal standards. The challenge encountered in the method development that the high plasma concentration level of acetaminophen made the MS response saturated while the desired lower limit of quantification(LLOQ) for oxycodone was hard to reach was well solved. The analytes were extracted by protein precipitation using acetonitrile. The matrix effect of the analytes was avoided by chromatographic separation using a hydrophilic C18 column coupled with gradient elution. Multiple reaction monitoring in positive ion mode was performed on tandem mass spectrometer employing electrospray ion source. The calibration curves were linear over the concentration ranges of 40.0–8000 ng/m L and 0.200–40.0 ng/m L for acetaminophen and oxycodone,respectively. This method, which could contribute to high throughput analysis and better clinical drug monitoring, was successfully applied to a pharmacokinetic study in healthy Chinese volunteers.
文摘Deoxyglycychloxazol(TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activity and reduced pseudoaldosteronism compared to glycyrrhetinic acid.In this study,a sensitive and rapid liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was established for the quantitation of TY501 in rat plasma.Plasma samples were treated by precipitating protein with methanol and supernatants were separated by a Symmetry C_8 column with the mobile phase consisting of methanol and 10 m M ammonium formate(containing 0.1% of formic acid)(90:10,v/v).The selected reaction monitoring(SRM) transitions were performed at m/z 647.4-191.2 for TY501 and m/z 473.3-143.3 for astragaloside aglycone(IS) in the positive ion mode with atmospheric pressure chemical ionization(APCI) source.Calibration curve was linear over the concentration range of 5–5000 ng/m L.The lower limit of quantification was 5 ng/m L.The mean recovery was over 88%.The intra- and inter-day precisions were lower than 6.0% and 12.8%,respectively,and the accuracy was within 7 1.3%.TY501 was stable under usual storage conditions and handling procedure.The validated method has been successfully applied to a pharmacokinetic study after oral administration of TY501 to rats at a dosage of 10 mg/kg.
文摘Liquid chromatography tandem mass chromatography(LC–MS/MS)is an important hyphenated technique for quantitative analysis of drugs in biological fuids.Because of high sensitivity and selectivity,LC–MS/MS has been used for pharmacokinetic studies,metabolites identifcation in the plasma and urine.This manuscript gives comprehensive analytical review,focusing on chromatographic separation approaches(column packing materials,column length and mobile phase)as well as different acquisition modes(SIM,MRM)for quantitative analysis of glucocorticoids and stimulants.This review is not meant to be exhaustive but rather to provide a general overview for detection and confrmation of target drugs using LC–MS/MS and thus useful in the doping analysis,toxicological studies as well as in pharmaceutical analysis.
文摘Management of cardiovascular risk factors in diabetes demands special attention due to their co-existence.Pioglitazone(PIO) and telmisartan(TLM) combination can be beneficial in effective control of cardiovascular complication in diabetes. In this research, we developed and validated a high throughput LC–MS/MS method for simultaneous quantitation of PIO and TLM in rat plasma. This developed method is more sensitive and can quantitate the analytes in relatively shorter period of time compared to the previously reported methods for their individual quantification. Moreover, till date, there is no bioanalytical method available to simultaneously quantitate PIO and TLM in a single run. The method was validated according to the USFDA guidelines for bioanalytical method validation. A linear response of the analytes was observed over the range of 0.005–10 μg/m L with satisfactory precision and accuracy. Accuracy at four quality control levels was within 94.27%–106.10%.The intra-and inter-day precision ranged from 2.32% to 10.14% and 5.02% to 8.12%, respectively. The method was reproducible and sensitive enough to quantitate PIO and TLM in rat plasma samples of a preclinical pharmacokinetic study. Due to the potential of PIO-TLM combination to be therapeutically explored, this method is expected to have significant usefulness in future.
文摘A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry(UPLC–MS/MS) method was developed and validated for the estimation of 17-desacetyl norgestimate in human plasma using solid-phase extraction technique. 17-desacetyl norgestimate D6 was used as the internal standard. Simple gradient chromatographic conditions and mass spectrometric detection enabled accurate and precise measurement of 17-desacetyl norgestimate at sub-picogram levels. The proposed method was validated for a linear range of 20–5000 pg/m L with a correlation coefficient Z 0.9988. The intra-run and inter-run precision and accuracy were within 10%. The overall recoveries for 17-desacetyl norgestimate and 17-desacetyl norgestimate D6 were 96.30% and 93.90%, respectively. The total run time was 4.5 min. The developed method was applied for the determination of the pharmacokinetic parameters of 17-desacetyl norgestimate following a single oral administration of a norgestimate and ethinyl estradiol0.250 mg/0.035 mg tablets in 35 healthy female volunteers.
